Defense Secretary Mattis reportedly wasn't consulted before the military dropped the 'mother of all bombs'

A Massive Ordnance Air Blast bomb Reuters Defense Secretary James Mattis was taken by surprise when the US Air Force dropped a Massive Ordnance Air Blast bomb, also known as the "Mother of All Bombs," on Islamic State targets in Afghanistan in April, according to a recent report in The New Yorker.

The decision to use the largest nonnuclear bomb in the US' arsenal was made by General John Nicholson, the Army general commanding forces in Afghanistan, and was not discussed with Mattis, which reportedly upset him.

President Donald Trump would not reveal whether he authorized the plan to drop the massive bomb, which had never before been used in combat, instead stating that he had given the military "total authorization."

The US government has refused to comment on the effects of the bombing, which targeted a cave complex in a remote region in the eastern part of the country, but Afghan officials say the attack killed 96 Islamic State militants. It is not clear whether any civilians were killed in the attack.

Mattis told reporters in April that the number of enemy combatants killed would not be released in part because body counts can be a misleading measurement of the effect of an attack.

"For many years we have not been calculating the results of warfare by simply quantifying the amount of enemy killed," Mattis said, adding, "Frankly, digging into tunnels to count dead bodies is probably not a good use of our troops time."

Since Trump took office, the US military has been given "considerably greater autonomy," Filkins wrote, allowing military leaders on the battlefield to pursue targets more aggressively than they could under President Barack Obama's leadership. The new approach, however, has reportedly led to a surge in civilian deaths associated with US attacks on militant targets in several countries, including Syria, Iraq, Afghanistan, Yemen, and Somalia.